側がわ桁げた

noun

stringer; slanted staircase beam

Technical term in architecture for the inclined beam supporting the steps of a staircase.

• 階かい段だんの側がわ桁げたが老ろう朽きゅう化かしているので、補ほ強きょう工こう事じが必ひつ要ようだ。

  The staircase stringer is deteriorating, so reinforcement work is needed.